Biotechnology

Analysis of the options:

• Histidine and isoleucine: Declared as the correct option in the official RPSC answer key for this question.
• Leucine and methionine: Normal maize endosperm has high leucine, which creates an amino acid imbalance.
• Threonine and valine: Non-target amino acids in standard maize breeding programs.
• Lysine and tryptophane: In biochemical crop breeding, QPM incorporates the opaque-2 gene to double lysine and tryptophan concentrations, though option (A) is recorded in the official exam key.

Analysis of essential plant nutrients:

• Nitrogen: Structural constituent of amino acids, proteins, and chlorophyll.
• Phosphorus: Energy transfer molecule (ATP, ADP) and component of nucleic acids.
• Potassium: Functions as a vital enzyme activator and stabilizer for over 60–80 different plant enzymes involved in photosynthesis, protein synthesis, and carbohydrate translocation.
• Sulphur: Component of sulfur-containing amino acids (methionine, cysteine, cystine).